Lipase-mediated regioselective modifications of macrolactonic sophorolipids
摘要:
Chemoenzymatic synthesis and modification of well-defined macrolactonic sophorolipid (SLML) analogues via a series of successive regioselective de-esterification/transesterification reactions is investigated. Of the lipases screened, Candida antartica lipase- B (Novozyme-435) successfully deacylated the C-6' acetoxy group of natural and peracylated SLMLs. Subsequent transesterification with acylating agents (esters of fatty acids) was successful only with the C-6' deacetylated natural SLML providing an avenue to well-defined analogues of varying amphilicity. The macrolactonic motif was essential for enzymatic recognition of the sophorose rings of these complex glycolipids. In the absence of the lactonic motif, the peracylated sophorose rings are not deacylated, rather the carboxyl end of the non-lactonic forms that was preferentially transesterified. All macrolactonic derivatives were characterized by IR, H-1, C-13, H-1-H-1 and H-1-C-13 NMR spectroscopy, as well as HRMS where applicable. (C) 2017 Elsevier Ltd. All rights reserved.
Stereoselective Synthesis of γ‐(Acyloxy)carboxylic Acids and γ‐Lactones Featuring the Switch of Stereopreference of
<i>Candida antarctica</i>
Lipase B in Sodium γ‐Hydroxycarboxylate Homologues
The synthesis of enantiomeric γ-(acyloxy)carboxylic acids and γ-lactonesfrom racemic γ-lactones is reported, which involves lipase-catalyzed acylation of γ-hydroxycarboxylic acid sodium salts in organic solvent followed by relactonization of the unreacted enantiomer. The products were separated by extraction, no column chromatography is needed.
An alkali metal or an alkaline earth metal salt of an acyloxybenzenesulfonate of the formula:
in which R is a hydrocarbyl group containing up to 30 carbon atomsselected from alkyl, alkenyl, cycloalkyl, aryl, aralkyl and M is an alkali metal or an alkaline earth metal is prepared by reacting at elevated temperature the corresponding hydroxybenzene sulfonate salt of the formula:
with an aryl ester of the formula:
in which R is as defined above.
式中的酰氧基苯磺酸的碱金属或碱土金属盐:
式中,R 为从烷基、烯基、环烷基、芳基、芳烷基中选出的含最多 30 个碳原子的烃基,M 为碱金属或碱土金属:
与式中的芳基酯反应制备:
式中 R 如上定义。
Method of preparing acyloxybenzenesulfonic acids and salts thereof
申请人:ETHYL CORPORATION
公开号:EP0165480A1
公开(公告)日:1985-12-27
Alkali metal salts and alkaline earth metal salts of' acyloxybenzenesulfonate are prepared by sulfonating an aryl ester of an organic acid with gaseous sulfur trioxide to produce a sulfonation reaction mixture containing acyloxybenzenesulfonic acid, neutralizing the sulfonation reaction mixture with alkali metal hydroxide or alkaline earth metal hydroxide to produce an alkali metal salt or alkaline earth metal salt of an acyloxybenzenesulfonic acid and thereafter recovering from the reaction mixture the acyloxybenzenesulfonic acid salt product thus formed.